Morphological Studies of Lightly Sulfonated Polystyrene Using 23Na NMR. 3. Effects of Humidification and Annealing

O'Connell, Ellen M.; Root, Thatcher W.; Cooper, Stuart L.

doi:10.1021/ma00115a036

Cited by 22 publications

(27 citation statements)

References 6 publications

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“…These field gradients can be especially due to the strong electric fields posed by other Na + ions or to polymer‐affixed anions, such as—SO

_{−}^{3}

groups, in the vicinity. It has been established that as peaks shift to less negative values, the interactions with Na + ions become weaker 24–32. This concept can be put to use in determining whether Na + ions are isolated or exist in aggregates, although the absolute size of these aggregates cannot be derived from this method.…”

Section: Resultsmentioning

confidence: 99%

Radial loop and extreme vessel tortuosity in the transradial approach: Advantage of hydrophilic‐coated guidewires and catheters

Barbeau

2003

Cathet Cardio Intervent

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Between October 2000 and October 2001, all transradial cases performed by the author necessitating radial and upper arm angiography because of difficult advancement of standard guidewires or catheters were analyzed retrospectively. Fourteen of 594 (2.4%) transradial cases met the study criteria. Radial loops or stenosis and tortuosity in the subclavian or innominate artery were responsible for the difficult access. Several examples of patients with access problems are presented. A technique using a hydrophilic-coated guidewire and a new hydrophilic-coated guiding catheter is described.

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“…These field gradients can be especially due to the strong electric fields posed by other Na + ions or to polymer‐affixed anions, such as—SO

_{−}^{3}

Section: Resultsmentioning

confidence: 99%

Radial loop and extreme vessel tortuosity in the transradial approach: Advantage of hydrophilic‐coated guidewires and catheters

Barbeau

2003

Cathet Cardio Intervent

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“…23 Na NMR experiments can be used to determine quantitatively the amount of isolated ions in sodium-neutralized ionomers; these experiments are critically important since they represent the only quantitative example where the fraction of isolated ions was determined for nontransition-metal neutralized materials. In a series of papers [29,[50][51][52], Cooper and coworkers used NMR to study NaSPS in great detail. The authors found that in fully neutralized samples at $2 mol% sulfonation level, the sodium atoms were both isolated and aggregated; while at $4 mol% sulfonation level, all sodium atoms were aggregated.…”

Section: Ionomer Synthesismentioning

confidence: 99%

Review and critical analysis of the morphology of random ionomers across many length scales

Grady

2008

Polymer Engineering & Sci

101

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This review presents a description of what is known about ionomer morphology. All papers on ionomer morphology are not included in this review; but all relevant questions about ionomer morphology are posed and answered as completely as possible. The review is critical; that is, reasons are given for morphologies that are deemed to be more or less likely. The review is organized along three length scales: sub-nanometer, nanometer to 10 nm, and greater than 10 nm. Within each length scale, all three phases are considered: crystalline, amorphous, and ionic aggregate. The purity of the three phases, the arrangement of atoms in the three phases, the size and shape of the three phases, and their arrangements in space relative to each other are explored in this review. A model for the shape of aggregates in ionomers that have well-ordered internal environments is presented. This model proposes that aggregates are fundamentally planar, but will ''roll up'' into tubes or other related structures in order to reduce the number of atoms at aggregate edges. This model was developed primarily based on the varied morphologies ionomers have shown in electron micrographs, but is consistent with other indirect measurements of ionomer morphology.

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“…The sodium nuclei existing in lone ion pairs yield a sharp peak centered around 7 ppm, while the sodium nuclei in the ionic aggregates (i.e. doublets, triplets,., multiplets) yield a broad peak centered in the range from K 8 to K12 ppm [22,[26][27][28][29]. Fig.…”

Section: Solid-state 23 Na Nmrmentioning

confidence: 97%

“…O'Connell et al [26][27][28][29] have shown that sodium ions in dry, lightly sulfonated polystyrene ionomers may exist in two distinctly different environments: (1) isolated sodium nuclei in lone sodium-sulfonate ion pairs and (2) sodium nuclei in close proximity to other sodium nuclei (i.e. in ionic aggregates).…”

Section: Solid-state 23 Na Nmrmentioning

confidence: 99%

Influence of ionic aggregation on the surface energies of crystallites in poly(butylene terephthalate) ionomers

Page

Schilling

Moore

2004

Polymer

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Morphological Studies of Lightly Sulfonated Polystyrene Using 23Na NMR. 3. Effects of Humidification and Annealing

Cited by 22 publications

References 6 publications

Radial loop and extreme vessel tortuosity in the transradial approach: Advantage of hydrophilic‐coated guidewires and catheters

Radial loop and extreme vessel tortuosity in the transradial approach: Advantage of hydrophilic‐coated guidewires and catheters

Review and critical analysis of the morphology of random ionomers across many length scales

Influence of ionic aggregation on the surface energies of crystallites in poly(butylene terephthalate) ionomers

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